14:28:01 <RRSAgent> RRSAgent has joined #dawg
14:28:01 <RRSAgent> logging to http://www.w3.org/2007/01/30-dawg-irc
14:28:04 <LeeF> zakim, this will be DAWG
14:28:04 <Zakim> ok, LeeF; I see SW_DAWG()9:30AM scheduled to start in 2 minutes
14:28:41 <LeeF> LeeF has changed the topic to: Data Access Working Group weekly telecon -- agenda: http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0055.html
14:28:51 <LeeF> Meeting: RDF DAWG Weekly
14:28:56 <LeeF> Agenda: http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0055.html
14:29:00 <LeeF> Chair: LeeF
14:29:07 <LeeF> Scribe: PatH
14:29:16 <LeeF> Regrets: EliasT, Jeen
14:29:27 <LeeF> agenda + Convene
14:29:32 <LeeF> agenda + Review ACTION Items
14:29:36 <sdas2> sdas2 has joined #dawg
14:29:38 <LeeF> agenda + Test suite
14:29:44 <LeeF> agenda + Blank node label scope
14:29:58 <LeeF> agenda + Extent of BGPs (vis a vis FILTERs)
14:30:07 <LeeF> agenda + Minimal test suite?
14:30:10 <Zakim> SW_DAWG()9:30AM has now started
14:30:14 <LeeF> agenda + rq25 status
14:30:17 <Zakim> +Simon_Raboczi
14:30:21 <LeeF> zakim, code?
14:30:21 <Zakim> the conference code is 7333 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), LeeF
14:30:45 <Zakim> +LeeF
14:31:34 <ericP> Zakim, please dial ericP-617
14:31:34 <Zakim> ok, ericP; the call is being made
14:31:35 <Zakim> +EricP
14:31:39 <Zakim> +Souri_Das
14:31:49 <LeeF> zakim, disconnect ericP
14:31:49 <Zakim> EricP is being disconnected
14:31:50 <Zakim> -EricP
14:32:01 <ericP> Zakim, please dial ericP-617
14:32:01 <Zakim> ok, ericP; the call is being made
14:32:02 <Zakim> +EricP
14:32:36 <Zakim> +??P1
14:32:38 <AndyS> zakim, ??P1 is me
14:32:38 <Zakim> +AndyS; got it
14:35:35 <Zakim> +Orri_Erling
14:35:42 <ericP> iv_an_ru_, meeting time
14:36:07 <LeeF> Scribe: LeeF
14:36:11 <LeeF> Jan 16. minutes http://www.w3.org/2007/01/16-dawg-minutes
14:36:30 <SimonR> (Sorry, it always does that and I have no idea how to turn it off.  It's probably a security feature...)
14:36:45 <LeeF> Approved, AndyS seconding
14:36:53 <LeeF> Jan 23. minutes http://www.w3.org/2007/01/23-dawg-minutes
14:37:17 <SimonR> Zakim, who's on the phone?
14:37:17 <Zakim> On the phone I see Simon_Raboczi, LeeF, EricP (muted), Souri_Das, AndyS, Orri_Erling
14:37:29 <LeeF> Approved, AndyS seconding
14:38:08 <SimonR> Meet again next week (Feb 6), SimonR to scribe
14:38:44 <LeeF> zakim, take up agenda 1
14:38:44 <Zakim> agendum 1. "Convene" taken up [from LeeF]
14:38:50 <LeeF> zakim, take up agenda 2
14:38:50 <Zakim> agendum 2. "Review ACTION Items" taken up [from LeeF]
14:39:04 <SimonR> LeeF: solicits comments on the agenda (additions, deletions) -- no requests from the group for changes
14:39:12 <LeeF> ACTION: AndyS to reply to  http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0041  
14:39:13 <LeeF> mentioning the possibility of banning the same bnode id from appearing in multiple BGPs in a query [DONE]
14:39:27 <LeeF> ACTION: LeeF to look back through minutes and mailing list to determine if the group has made a past decision on blank node scope [DONE]
14:39:53 <LeeF> ACTION: AndyS to reply to Bob M noting changes in examples in curent algebra [CONTINUES]
14:40:02 <LeeF> ACTION: EricP to run the yacker tool over and annotate the existing tests [CONTINUES]
14:40:10 <LeeF> ACTION: Jeen to mark approved tests as dawg:approved [CONTINUES]
14:40:11 <AndyS> No progess on my action item.
14:40:20 <LeeF> ACTION: LeeF to remember that the wee, lost filter tests should be put  [CONTINUES]
14:40:30 <LeeF> zakim, take up agendum 3
14:40:30 <Zakim> agendum 3. "Test suite" taken up [from LeeF]
14:40:50 <LeeF> Test sutie status from Jeen: http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0050.html
14:40:57 <LeeF> agendum, take up agendum 4
14:41:03 <LeeF> zakim, take up agendum 4
14:41:03 <Zakim> agendum 4. "Blank node label scope" taken up [from LeeF]
14:42:19 <LeeF> LeeF: <explains blank node label scope issue as per http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0055.html>
14:42:34 <LeeF> AndyS: Sometimes you need to use blank node labels instead of square brackets (e.g. shared objects)
14:43:11 <LeeF> AndyS: Question is then what is the scope of these labels -- right now you can't refer to one blank node from a different BGP, but you can reuse the label to mean a different bnode
14:43:13 <LeeF> ... this is confusing
14:43:15 <patH> patH has joined #dawg
14:43:29 <LeeF> ... I'd rather put the burden on the application writer so that it is something that is caught by the parser
14:43:48 <ericP> Zakim, ack me
14:43:48 <Zakim> unmuting EricP
14:43:49 <Zakim> I see no one on the speaker queue
14:44:17 <LeeF> ericP: I'm content with that restriction; 
14:44:31 <SimonR> If I recall correctly, we prohibit a variable from being reused between parallel OPTIONAL clauses.  I'm still of the impression that when the bnode syntax occurs in a query, it's not an existential (as it would be in a graph), but an `undistinguished' variable.  So, the prohibition of reusing variable labels would apply to the undisinguished ones as well.
14:44:51 <Zakim> +PatH
14:45:04 <AndyS> SimonR : not any more.  Can reuse the var - has a natural meaning in the algebra.
14:45:06 <patH> hi, sorry late
14:45:31 <SimonR> AndyS: Turns it into some sort of UNION...?
14:45:50 <ericP> scribe: patH 
14:46:00 <AndyS> Turns it into "try this, if not try that"
14:46:09 <Zakim> -LeeF
14:46:21 <iv_an_ru_> iv_an_ru_ has joined #dawg
14:46:31 <Zakim> +LeeF
14:46:33 <SimonR> AndyS, so the order of the OPTIONAL clauses makes a difference now?
14:46:57 <AndyS> SimonR : yes - that is true for SQL left join as well (in the same way)
14:47:06 <LeeF> Straw poll: What do you think about the proposal to make it illegal to include the same blank node label in multiple BGPs in a single query?
14:47:13 <LeeF> zakim, who's here?
14:47:13 <Zakim> On the phone I see Simon_Raboczi, EricP, Souri_Das, AndyS, Orri_Erling, PatH, LeeF
14:47:15 <Zakim> On IRC I see iv_an_ru_, patH, sdas2, RRSAgent, Zakim, AndyS, SimonR, afs, SteveH, LeeF, ericP
14:47:37 <patH> simon:like it
14:48:08 <patH> eric:yep
14:48:14 <patH> suri:happy
14:48:30 <SimonR> If two things are different, the syntax checker forces you to label them differently.
14:48:58 <patH> ori:good
14:49:15 <patH> pat:as good as itgets
14:49:23 <SimonR> PatH: Doesn't like it, but supports it as the lesser evil
14:49:38 <patH> lee:pity about invalidating existing, but good
14:50:18 <LeeF> PROPOSED: Blank node labels are scoped to the BGP in which they appear; it is an illegal query to include the same blank node label in multiple BGPs in a single query
14:51:24 <patH> pat:second
14:51:37 <LeeF> RESOLVED
14:52:12 <LeeF> ACTION: AndyS to add text clarifying this resolution to rq25
14:52:16 <LeeF> ACTION -7
14:52:29 <LeeF> ACTION: AndyS to add test clarifying the prohibition on blank node labels in multiple BGPs to rq25
14:52:41 <LeeF> zakim, take up agendum 5
14:52:41 <Zakim> agendum 5. "Extent of BGPs (vis a vis FILTERs)" taken up [from LeeF]
14:52:43 <AndyS> s/test/text/
14:53:24 <LeeF> Andy's test cases on blank node label scope: http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0056.html
14:53:40 <LeeF> Andy's test case on the extent of BGPs: http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0052.html
14:54:37 <AndyS> Example: { <x> :p _:a . FILTER(true) . <x> :q _:a }
14:54:39 <patH> Issue: does a filter break a BGP into two BGPs?
14:55:58 <LeeF> AndyS: tension between principles of FILTERs applying to group and BGPs being adjacent triple patterns
14:56:39 <LeeF> AndyS: If we decide that FILTERs do not break-up a BGP then we probably want a slight grammar change
14:57:02 <ericP> me
14:57:06 <sdas2> Was there ever a discussion on banishing FILTER to the far right end?
14:57:41 <LeeF> ericP: I'm imagining a pattern of query writing that highly interleaves triple patterns with the constraints on those patterns, and I'd like to be able to include the same  blank node through all of those
14:57:42 <AndyS> Souri - yes - there has been a little.  
14:58:06 <AndyS> A balance between that and placing close to the thing it restricts.
14:59:39 <ericP> { _:who foaf:mbox ?mbox FILTER regexp(?mbox, "^mailto:") _:who foaf:name ?name FILTER LANGMATCHES(?name "EN") }
15:00:50 <LeeF> patH: Feels strange to have FILTERs break up scoping which is otherwise in line with the curly braces
15:01:26 <AndyS> c.f. inserting OPTIONAL or even {} which will break the BGP regardless.
15:02:00 <LeeF> AndyS: the principle for demarkating the edges of a BGP has been adjacency of triples
15:02:33 <LeeF> other example: { _:a <p> <o> . { ?x ?y ?z } . _:a <p2> <o2> }
15:03:53 <sdas2> That looks like three BGPs.
15:04:22 <AndyS> { _:a <p> <o> . OPTIONAL { ?x ?y ?z } . _:a <p2> <o2> }
15:05:05 <ericP> { ?a <p> <o> . ?a <p2> <o2> OPTIONAL { ?x ?y ?z } }
15:05:18 <ericP> { ?a <p> <o> OPTIONAL { ?x ?y ?z } . ?a <p2> <o2> }
15:05:53 <LeeF> ericP: is there a difference between the above two constructs?
15:06:05 <LeeF> AndyS: In simple entailment, no; but in higher entailments, perhaps.
15:06:22 <ericP> { _:a <p> <o> . OPTIONAL { ?x ?y ?z } . _:a <p2> <o2> }
15:06:27 <ericP> A
15:06:30 <AndyS> Different again: {OPTIONAL { ?x ?y ?z } .  { ?a <p> <o>  } ?a <p2> <o2> }
15:06:39 <ericP> { ?a <p> <o> . ?a <p2> <o2> OPTIONAL { ?x ?y ?z } }
15:07:33 <LeeF> patH: If we decided that that *is* one BGP, then that's the way it is and it could/would be sent to a (e.g.) DL engine that way
15:08:37 <LeeF> <discussion of what's the nice design here>
15:08:43 <AndyS> UNION, GRAPH, extra {}
15:08:53 <LeeF> ericP: possibility, say FILTER does not break up BGPs ...
15:10:06 <ericP> '{' pattern '}'
15:10:57 <LeeF> AndyS: I would probably change the production rule name 
15:11:12 <LeeF> zakim, who''s here?
15:11:13 <Zakim> I don't understand your question, LeeF.
15:11:17 <LeeF> zakim, who's here?
15:11:17 <Zakim> On the phone I see Simon_Raboczi, EricP, Souri_Das, AndyS, Orri_Erling, PatH, LeeF
15:11:19 <Zakim> On IRC I see iv_an_ru_, patH, sdas2, RRSAgent, Zakim, AndyS, SimonR, afs, SteveH, LeeF, ericP
15:11:39 <LeeF> straw poll: What's your feeling on whether a FILTER should break up a BGP?
15:11:57 <LeeF> patH: does not break up
15:12:45 <LeeF> Orri: at first no, but concerns over passing parts to reasoning engines 
15:13:18 <LeeF> Orri: slight preference for not breaking it up
15:13:24 <LeeF> AndyS: slight preference for breaking it up
15:13:34 <LeeF> Souri: prefer not breaking it up 
15:14:11 <LeeF> Souri: (since we can always push filters to the end (eqiuvalent meaning), then they shouldn't break up a BGP 
15:14:32 <patH> thnks eric. He is always faster then me :(
15:14:34 <patH> { _:a <p> <o> . OPTIONAL { ?x ?y ?z } . _:a <p2> <o2> }
15:14:48 <patH> ?how did tht happen? never mind
15:14:59 <LeeF> ericP: not breaking it up
15:15:45 <LeeF> SimonR: not break it up
15:16:19 <patH> good man
15:17:42 <LeeF> PROPOSED: FILTER clauses do not break up a BasicGraphPattern; a BGP is an adjacent block of triples, possibly with interleaved FILTER clauses 
15:18:12 <LeeF> ericP seconds
15:18:29 <SimonR> AndyS: abstains
15:18:34 <LeeF> RESOLVED, AndyS abstaining
15:19:08 <LeeF> ACTION: AndyS to clarify the extent of BGPs is not broken up by FILTER clauses and to change production rule name in the grammar
15:19:52 <LeeF> agenda + ericP and existential nature of bnodes
15:20:09 <LeeF> zakim, take up agendum 8
15:20:09 <Zakim> agendum 8. "ericP and existential nature of bnodes" taken up [from LeeF]
15:21:09 <LeeF> ericP: I think in a bag language such as SPARQL that existentials have a cardinality of 0 or 1
15:21:45 <LeeF> ericP: current rq25 text uses the word "existential" to describe blank nodes
15:23:00 <LeeF>  http://lists.w3.org/Archives/Public/public-rdf-dawg/2006OctDec/att-0175/28-dawg-minutes.html#item04
15:24:08 <AndyS> Text in http://www.w3.org/2001/sw/DataAccess/rq23/rq25.html#QSynBlankNodes
15:24:31 <AndyS> """Blank nodes in query patterns act as existential variables, not as references to specific blank nodes in the data being queried."""
15:25:24 <AndyS> If it's the text that a problem, what would be better text?
15:25:33 <SimonR> I'm (still) under the impression that graph patterns *never* contain real existential bnodes in the same way that RDF graphs do.  You could never assert that an existential in a graph is the same existential in your query, which we determined wasn't very useful back in November.  We use the same syntax that was developed for bnodes in graph patterns, but it means undistinguished variables instead.
15:25:55 <SimonR> See Definition 4 in http://www.debruijn.net/publications/ppswr-05.pdf
15:27:53 <patH> Simon, there isnt a real diference between undistinguished varaible and existential when we are limited to simple (or RDF.RDFS) entailment. They are the same.
15:28:05 <patH> Until you get to the DL case.
15:28:44 <SimonR> Pat, okay, let me meditate upon that.  :)
15:29:07 <LeeF> AndyS: I think would be tough to map to SQL with a cardinality of 1 because can't have partial DISTINCT projections in SQL
15:29:28 <patH> Simon, the killer change in DL is that the language has disjunction in it. So the 'binding' can be either-this-or-that.
15:30:12 <SimonR> Pat, ahhhhh...
15:31:42 <AndyS> This is the only use of "existential" in rq25.
15:34:33 <SimonR> Pat, it would be okay to treat existentials and non-distinguished variables until to get to an interpretation with disjunction in (such as DL), in which case it causes problems.
15:34:51 <SimonR> (Oops, should've been "Pat:" there)
15:34:58 <LeeF> +2s/Pat,/Pat:
15:41:44 <patH> much discussion of wording of 4.1.4. Lee thinks essential point is this sets up to fix a possible misunderstanding. Andy thinks nondistinguished better than existential.  
15:41:50 <patH> maybe.
15:41:53 <sdas2> Aside: Is '?' right in Rule [13] ('WHERE' ? GroupGraphPattern)
15:42:12 <SimonR> We have two kinds of interpretation functions, the ones that satisfy the RDF graph's model (which interpret the bnodes) and the query solutions (which interpret the query variables, nondistinguished and otherwise).
15:42:21 <LeeF> Souri, yes, the WHERE keyword is optional
15:43:32 <sdas2> I see. So, SELECT ?x {?x :name <John>} is ok?
15:43:58 <AndyS> Souri, yes.
15:44:11 <sdas2> Thx.
15:44:13 <AndyS> ASK { ?x :name "John" }
15:44:28 <LeeF> zakim, take upa gendum 7
15:44:28 <Zakim> I don't understand 'take upa gendum 7', LeeF
15:44:35 <SimonR> Accept-language: en-SQL, en-logician, en-webdeveloper
15:44:58 <AndyS> unsatisfiable!
15:45:31 <patH> Pat apologises in writing for being a lousy scribe.
15:45:41 <Zakim> -Orri_Erling
15:45:41 <AndyS> ADJOURN
15:45:43 <Zakim> -Souri_Das
15:45:45 <Zakim> -PatH
15:45:46 <SimonR> ADJOURNED at 15:45 Z
15:45:46 <Zakim> -EricP
15:45:53 <Zakim> -LeeF
15:45:57 <LeeF> ericP, I"ll get the minutes to you in a few days
15:45:58 <Zakim> -AndyS
15:46:03 <LeeF> rrsagent, please generate minutes
15:46:03 <RRSAgent> I have made the request to generate http://www.w3.org/2007/01/30-dawg-minutes.html LeeF
15:46:07 <Zakim> -Simon_Raboczi
15:46:09 <LeeF> rrsagent, make logs world-access
15:46:11 <Zakim> SW_DAWG()9:30AM has ended
15:46:13 <Zakim> Attendees were Simon_Raboczi, LeeF, EricP, Souri_Das, AndyS, Orri_Erling, PatH
15:46:22 <AndyS> zakim, please leave
15:46:22 <Zakim> Zakim has left #dawg
15:46:36 <AndyS> rrsagent, please leave
15:46:36 <RRSAgent> I see 8 open action items saved in http://www.w3.org/2007/01/30-dawg-actions.rdf :
15:46:36 <RRSAgent> ACTION: AndyS to reply to  http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JanMar/0041   [1]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-39-12
15:46:36 <RRSAgent> ACTION: LeeF to look back through minutes and mailing list to determine if the group has made a past decision on blank node scope [DONE] [2]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-39-27
15:46:36 <RRSAgent> ACTION: AndyS to reply to Bob M noting changes in examples in curent algebra [CONTINUES] [3]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-39-53
15:46:36 <RRSAgent> ACTION: EricP to run the yacker tool over and annotate the existing tests [CONTINUES] [4]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-40-02
15:46:36 <RRSAgent> ACTION: Jeen to mark approved tests as dawg:approved [CONTINUES] [5]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-40-10
15:46:36 <RRSAgent> ACTION: LeeF to remember that the wee, lost filter tests should be put  [CONTINUES] [6]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-40-20
15:46:36 <RRSAgent> ACTION: AndyS to add test clarifying the prohibition on blank node labels in multiple BGPs to rq25 [8]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T14-52-29
15:46:36 <RRSAgent> ACTION: AndyS to clarify the extent of BGPs is not broken up by FILTER clauses and to change production rule name in the grammar [9]
15:46:36 <RRSAgent>   recorded in http://www.w3.org/2007/01/30-dawg-irc#T15-19-08
15:46:43 <AndyS> simon, please stop recording